Bring in the Birds

Each year, I eagerly anticipate the arrival of the colorful and gregarious evening grosbeak in my front courtyard garden. These robin-sized, stocky birds bring with them a sense of presence and an easygoing, light-hearted manner. Sadly, the evening grosbeak belongs to a group of 20 common backyard bird species whose populations have fallen by at least half in the past 40 years.

Birds that were once common as little as a decade ago are becoming increasingly scarce today. The evening grosbeak, in fact, has taken a drastic nosedive in numbers, plummeting by 78 percent in the past 40 years. Pesticide use, climate change, pollution, and even cats—both feral and domestic—have taken their toll, but a reduction in birds' most basic need—habitat—is critical. "Most of the decline can be attributed to habitat destruction both in North America and their wintering grounds in Central and South America," says Roger Lederer, Ph.D., professor emeritus of biological sciences at California State University in Chico and editor of Ornithology.com.

While the evening grosbeaks are becoming more of a rarity, the total avian population in my garden has soared over the years. Now I look forward to the arrival of more than 30 different bird species right outside my front door. By incorporating the right mix of plants—in addition to amenities such as feeders, birdhouses, and baths—you too can welcome birds with the essentials we all need for survival: food, water, shelter, and a place to raise a family.

Natural Shelter
Birds need a safe place where they can hide from predators and seek protection from harsh weather. They also need places to perch, settle in for the night, and raise their young. You can help meet all these needs by including a mix of both evergreen and deciduous trees and shrubs. Many of these plants also double the avian appeal by providing seeds, fruits, nuts, and nectar.

Conifers, such as spruces, firs, and pines, as well as evergreen trees and shrubs like holly and some cotoneasters, provide year-round shelter for birds. Elderberries, maples, and other deciduous plants offer seasonal shelter and summer nesting sites. Combinations of both deciduous and evergreen plants form the framework of successful bird gardens because together they create a four-season safety zone, habitat site, and food source, especially when arranged as a windbreak or natural hedgerow.

Nesting Instinct
Adding nest boxes to your garden provides a housing opportunity to songbirds that nest in cavities rather than on the ground or in the branches of shrubs and trees. Which species will inhabit the box depends on where you live, the surrounding habitat, and the construction and placement of the nest box.

"When setting out new nest boxes, consider the preferred habitat for different species, as well as the size of the entrance hole, and its distance above the ground," notes Stephen W. Kress, Ph.D., vice president for bird conservation for the National Audubon Society and author of the Audubon Society Guide to Attracting Birds.

Generally, a nest box with an entrance hole diameter between 1¼ and 1½ inches, and placed 8 to 12 feet above the ground, will suffice for most cavity-nesting backyard bird species while preventing starlings (an aggressive, nonnative species) from moving in. The best location for most any nest box is in an area protected from direct sun with the entrance hole facing away from prevailing winds.

Edible Plantings
Most backyard birds are opportunistic feeders. While every bird species has its own unique food requirements, the type of food they eat often changes with the environment, the seasons, and the age of the bird. For example, finches are frequent visitors at backyard seed feeders, but they also eat a few buds in spring, insects in summer, and berries in fall. And many species of birds that typically gorge on insects switch to a diet rich in berries when migrating in fall.

Growing a diversity of food-bearing plants will help ensure an all-you-can-eat bird buffet by providing nourishing nuts, seeds, fruits, berries, buds, and nectar (for hummingbirds and orioles) throughout the year. Red mulberry and sassafras are good berry sources in spring and summer, viburnums offer berry sustenance in summer and fall, and the fruit of hollies and hawthorns ripen in fall and, in some species, last into early spring. And because an organic garden is also home to a variety of insects and caterpillars, there's always a ready food source for robins, swallows, and other birds that rely on insects as part or most of their diet.

Feeder Features
As essential as plant diversity is to attracting a greater number of bird species, offering supplementary food via a bird feeder can add that extra element of enticement—especially in winter when seeds, insects, and other foods are in short supply. You can cater to different species of birds by offering seeds they like, such as nyjer seed for finches. Or fill your feeders with black-oil sunflower seeds, which appeal to the widest variety of bird species. This bird-feeding strategy also eliminates the waste that often comes with birdseed mixes. If you do use a birdseed mix, opt for one that contains mostly black-oil sunflower seeds mixed with millet and cracked corn. Feeding birds helps bridge the gap when winter food sources dwindle, but designing a bird-friendly landscape is better for bird populations in the long run because it provides not just food but also a place to live and breed.

Watering Essentials
For birds, finding fresh water can often be more elusive than food. Well-planned bird gardens supply water year-round for drinking and bathing. Providing water can be as easy as putting out a few birdbaths, or you can take on a more challenging project by installing a pond complete with a waterfall.

The sound of running water attracts birds. If your water source is small, they may not be able to see it from a distance, but they often hear the sound. Waterfalls, gurgling fountains, or the gentle trickle from a birdbath drip system will bring in birds and make your water feature less hospitable to mosquitoes looking for a place to lay eggs.

Water sources don't need to be manmade or store-bought. Hostas, dogwoods, and other plants with concave surfaces collect pools of water that make the perfect-sized bath for hummingbirds, warblers, and other smaller birds. Even a natural depression in a rock or plastic-lined hollow in the soil can serve as a simple water source. "Any kind of depression that receives rainfall or gets wetted by a sprinkler system holds water for a day or two," Lederer says.

Planning Your Plantings
A good landscaping plan helps combat habitat loss and increases bird populations and the number of species you see. Offering creature comforts as a four-season, multilayered package of groundcovers, vines, plants, trees, and shrubs—both deciduous and evergreen—is essential to attracting birds. But the key to designing a garden that is a popular bird destination spot, not just a fleeting stopover, is to grow a diverse range of plants and plan the habitat using three basic landscaping principles: unity, variety, and transition.

Unity. From a bird's-eye view, a solitary plant doesn't hold much impact. Birds are much more likely to flock to a large grouping of plants. Large drifts or plant clusters also appeal to people, because they appear more spontaneous and natural and make a landscape look cohesive.

Variety. A mix of plant sizes, colors, textures, and season of bloom brings in a variety of birds by offering different foraging opportunities and maximum year-round habitat. For example, flowering trees, shrubs, and vines that offer fruit during different seasons provide four-season sustenance for birds along with year-round interest for you and your family.

Transition. Different species of birds exist at different levels of the vertical space between the tree canopy and the soil. Juncos, for example, are ground-feeding and ground-nesting birds, whereas nuthatches nest and typically feed in trees. In a bird-friendly garden, the plants transition naturally from groundcovers to perennials and shrubs to trees—creating a multilayered habitat that appeals to a wide range of species.

Planning your garden, whatever its size, with birds in mind makes a critical difference in their survival rates—especially for birds that migrate. "It's like stopping at a gas station on a long, cross-country drive—they get enough food and rest to keep them going, at least until the next stop," says ornithologist Andy Forbes, director of bird conservation at Audubon Missouri. "A garden can be a lifesaver for a bird that has been knocked down or thrown off course by inclement weather. Of course, planting a bird garden impacts the gardener as well," notes Lederer. "Birds are ecological indicators—their changes in population reflect what is happening to the larger environment," he says. "Everything we do to replace what we have paved over will make life more pleasant for us as well as the birds."